PSU not enough power?

[RC159]

I put a PC together a couple months ago. Now when I turn it on I get nothing, psu fan not even spinning. I put a 235 watt PSU in to see if the PSU was the problem. The motherboard has the 4 pin 12V connector, the 235 watt PSU I'm using to test it does not have the 4 pin 12v plug. When I turn on the PC it lights up but wont boot, I hear no beeps or nothing. Is it because the 235 watt PSU cant handle the PC? The PSU that was in it is a 450watt with the 4 pin 12V connector.

 

[Modelworks]

The 4 pin connector is required.
It powers the cpu power supply.

On the 450 watt power supply , unplug it from the motherboard, but leave the drives connected.
On the motherboard connector of the power supply use a short wire to jumper the green wire with a black wire. The power supply should come on .

That will rule out the power button on the front of your case or the motherboard not sending the correct signal to the power supply.

If it doesn't come on with the jumper in place the supply is bad.
If it does come on with the jumper in place, its either the motherboard or the case power switch.

 

[RC159]

Modelworks, Thanks for the info. I tried what you said. I have a bad PSU.